New regression equations for mixed dentition space analysis in Nepalese mongoloids

Area of Science:

• Orthodontics and Dental Anthropology
• Craniofacial Growth and Development
• Predictive Modeling in Dentistry

Background:

• Commonly used mixed dentition space analyses, Moyers' and Tanaka-Johnston, rely on regression equations.
• Previous studies have questioned the applicability of these analyses across diverse racial groups.
• Assessing the accuracy of existing methods for specific ethnic populations is crucial for effective orthodontic treatment planning.

Purpose of the Study:

• To evaluate the applicability of Moyers' and Tanaka-Johnston analyses in Nepalese Mongoloid patients.
• To determine if existing regression equations accurately predict tooth widths in this population.
• To develop new, population-specific regression equations if current methods prove inadequate.

Main Methods:

• One hundred pre-treatment orthodontic study models from Nepalese Mongoloid patients (50 males, 50 females) were analyzed.
• Mesiodistal widths of mandibular incisors, and canine and premolar teeth were measured using digital calipers.
• Predicted tooth widths were calculated using standard Moyers' and Tanaka-Johnston analyses and compared to measured values.

Main Results:

• Significant discrepancies were observed between measured and predicted canine and premolar widths using both Moyers' and Tanaka-Johnston analyses.
• Strong positive correlations were found between incisor widths and canine/premolar widths in both male and female Nepalese Mongoloid patients.
• Correlation coefficients ranged from 0.64 to 0.79, indicating a potential for developing predictive equations.

Conclusions:

• Moyers' and Tanaka-Johnston analyses do not provide accurate predictions for unerupted canine and premolar mesiodistal widths in Nepalese Mongoloids.
• New regression equations were developed specifically for the Nepalese Mongoloid population to enhance prediction accuracy.
• Further validation studies are recommended to confirm the clinical applicability and precision of the newly developed equations.